Black And White Printing Services Twin Cities MN
Color Flyers in Twin Cities MN
Digital printing in Minnesota has been a door opener for many businesses. Because printers sell the same thing as everyone else, everyone tries to claim that their service, quality and price are better than others. For this reason, every printer has to find something that would separate them from everyone else. And some business owners find that they have increased productivity after using digital technology and short run processes. Somehow, these gains can be credited to a combination of better pricing and more efficient press performance. Let’s say you have greeting cards that need to be printed. Obsolete inventory through the use of short run digital press can be eliminated.
Color Flyers in Twin Cities MN
This is because with this technology you can print only the needed cards, thus, resulting to orders printed in the exact quantity required. But just the same this kind of printing system is not for everyone. There are risks and changes that need to be dealt with. Nevertheless, the printing industry will continue to change and improve in the years to come. Thus, all business owners and companies have to do is to determine whether this certain printing technique is what they need.
Digital Color Prints vs Color Copies
The earliest surviving camera photograph, 1826 or 1827, known as View from the Window at Le Gras The history of photography has roots in remote antiquity with the discovery of two critical principles, that of the camera obscura (darkened or obscured room or chamber) and the fact that some substances are visibly altered by exposure to light, as discovered by observation. As far as is known, nobody thought of bringing these two phenomena together to capture camera images in permanent form until around 1800, when Thomas Wedgwood made the first reliably documented, although unsuccessful attempt. In the mid-1820s, Nicéphore Niépce succeeded, but several days of exposure in the camera were required and the earliest results were very crude. Niépce's associate Louis Daguerre went on to develop the daguerreotype process, the first publicly announced and commercially viable photographic process. The daguerreotype required only minutes of exposure in the camera, and produced clear, finely detailed results. It was commercially introduced in 1839, a date generally accepted as the birth year of practical photography. The metal-based daguerreotype process soon had some competition from the paper-based calotype negative and salt print processes invented by William Henry Fox Talbot. Subsequent innovations made photography easier and more versatile. New materials reduced the required camera exposure time from minutes to seconds, and eventually to a small fraction of a second; new photographic media were more economical, sensitive or convenient, including roll films for casual use by amateurs. In the mid-20th century, developments made it possible for amateurs to take pictures in natural color as well as in black-and-white. The commercial introduction of computer-based electronic digital cameras in the 1990s soon revolutionized photography. During the first decade of the 21st century, traditional film-based photochemical methods were increasingly marginalized as the practical advantages of the new technology became widely appreciated and the image quality of moderately priced digital cameras was continually improved. The coining of the word "photography" is usually attributed to Sir John Herschel in 1839. It is based on the Greek φῶς (phōs), (genitive: phōtós) meaning "light", and γραφή (graphê), meaning "drawing, writing", together meaning "drawing with light". A camera obscura used for drawing Photography is the result of combining several different technical discoveries. Long before the first photographs were made, Greek mathematicians Aristotle and Euclid described a pinhole camera in the 5th and 4th centuries BCE. In the 6th century CE, Byzantine mathematician Anthemius of Tralles used a type of camera obscura in his experiments Ibn al-Haytham (Alhazen) (965 in Basra – c. 1040 in Cairo) studied the camera obscura and pinhole camera, Albertus Magnus (1193/1206–80) discovered silver nitrate, and Georges Fabricius (1516–71) discovered silver chloride. Daniel Barbaro described a diaphragm in 1568. Wilhelm Homberg described how light darkened some chemicals (photochemical effect) in 1694. The novel Giphantie (by the French Tiphaigne de la Roche, 1729–74) described what could be interpreted as photography. The earliest known surviving heliographic engraving, made in 1825. It was printed from a metal plate made by Joseph Nicéphore Niépce with his "heliographic process". The plate was exposed under an ordinary engraving and copied it by photographic means. This was a step towards the first permanent photograph from nature taken with a camera obscura. In 1614, Angelo Sala demonstrated that "powdered silver nitrate is blackened by the sun", as was paper that was wrapped around it. This discovery of the sun's effect on powdered silver nitrate was not supported and was subsequently disregarded by then-respected scientists who said that his discovery "had no practical application." Around 1717,[n 1] Johann Heinrich Schulze, a German professor of anatomy and physics, set down a bottle containing silver nitrate and chalk by the window and unintentionally in the path of incoming light from the sun. The mixture, unsurprisingly, turned dark. But what he noticed and found to be strange was that part of it remained white and formed a line across the bottle. He then observed a cord hanging down and going across in front of the window, which he found out to be the cause. On further examination, he found that the entire mixture inevitably reverted to its original white color. Experimenting further, Schulze succeeded in transferring words he pasted on the bottle printed into the substance. Describing his achievement, Schulze wrote that “[t]he sun’s rays, where they hit the glass through the cut-out parts of the paper, wrote each word or sentence on the chalk precipitate so exactly and distinctly that many who were curious about the experiment but ignorant of its nature took occasion to attribute the thing to some sort of trick.” He put the silver nitrate in an oven, which had no effect on its color. This proved to him, definitively, that heat had not facilitated the transformation, as popularly suspected. Rather, it was the light. In 1777, the chemist Carl Wilhelm Scheele was studying the more intrinsically light-sensitive silver chloride and determined that light darkened it by disintegrating it into microscopic dark particles of metallic silver. Of greater potential usefulness, Scheele found that ammonia dissolved the silver chloride but not the dark particles. This discovery, which could have been used to stabilize or "fix" a camera image captured with silver chloride, was little-noticed at the time and unknown to the earliest photography experimenters. It was not until around the year 1800 that Thomas Wedgwood made the first known attempt to capture the image in a camera obscura by means of a light-sensitive substance. He used paper or white leather treated with silver nitrate. Although he succeeded in capturing the shadows of objects placed on the surface in direct sunlight, and even made shadow-copies of paintings on glass, it was reported in 1802 that "[t]he images formed by means of a camera obscura have been found too faint to produce, in any moderate time, an effect upon the nitrate of silver." The shadow images eventually darkened all over because "[n]o attempts that have been made to prevent the uncoloured part of the copy or profile from being acted upon by light have as yet been successful." Wedgwood may have prematurely abandoned his experiments due to frail and failing health; he died aged 34 in 1805. "Boulevard du Temple", a daguerreotype made by Louis Daguerre in 1838, is generally accepted as the earliest photograph to include people. It is a view of a busy street, but because the exposure lasted for several minutes the moving traffic left no trace. Only the two men near the bottom left corner, one of them apparently having his boots polished by the other, remained in one place long enough to be visible. In 1816 Nicéphore Niépce, using paper coated with silver chloride, succeeded in photographing the images formed in a small camera, but the photographs were negatives, darkest where the camera image was lightest and vice versa, and they were not permanent in the sense of being reasonably light-fast; like earlier experimenters, Niépce could find no way to prevent the coating from darkening all over when it was exposed to light for viewing. Disenchanted with silver salts, he turned his attention to light-sensitive organic substances. Robert Cornelius, self-portrait, October or November 1839, an approximately quarter plate size daguerreotype. On the back is written, "The first light picture ever taken". One of the oldest photographic portraits known, 1839 or 1840, made by John William Draper of his sister, Dorothy Catherine Draper Not all early portraits are stiff and grim-faced records of a posing ordeal. This pleasant expression was captured by Mary Dillwyn in Wales in 1853. The oldest surviving photograph of the image formed in a camera was created by Niépce in 1826 or 1827. It was made on a polished sheet of pewter and the light-sensitive substance was a thin coating of bitumen, a naturally occurring petroleum tar, which was dissolved in lavender oil, applied to the surface of the pewter and allowed to dry before use. After a very long exposure in the camera (traditionally said to be eight hours, but now believed to be several days), the bitumen was sufficiently hardened in proportion to its exposure to light that the unhardened part could be removed with a solvent, leaving a positive image with the light areas represented by hardened bitumen and the dark areas by bare pewter. To see the image plainly, the plate had to be lit and viewed in such a way that the bare metal appeared dark and the bitumen relatively light. In partnership, Niépce in Chalon-sur-Saône and Louis Daguerre in Paris refined the bitumen process, substituting a more sensitive resin and a very different post-exposure treatment that yielded higher-quality and more easily viewed images. Exposure times in the camera, although substantially reduced, were still measured in hours. Niépce died suddenly in 1833, leaving his notes to Daguerre. More interested in silver-based processes than Niépce had been, Daguerre experimented with photographing camera images directly onto a mirror-like silver-surfaced plate that had been fumed with iodine vapor, which reacted with the silver to form a coating of silver iodide. As with the bitumen process, the result appeared as a positive when it was suitably lit and viewed. Exposure times were still impractically long until Daguerre made the pivotal discovery that an invisibly slight or "latent" image produced on such a plate by a much shorter exposure could be "developed" to full visibility by mercury fumes. This brought the required exposure time down to a few minutes under optimum conditions. A strong hot solution of common salt served to stabilize or fix the image by removing the remaining silver iodide. On 7 January 1839, this first complete practical photographic process was announced at a meeting of the French Academy of Sciences, and the news quickly spread. At first, all details of the process were withheld and specimens were shown only at Daguerre's studio, under his close supervision, to Academy members and other distinguished guests. Arrangements were made for the French government to buy the rights in exchange for pensions for Niépce's son and Daguerre and present the invention to the world (with the exception of Great Britain, where an agent for Daguerre patented it) as a free gift. Complete instructions were made public on 19 August 1839. Known as the Daguerreotype process, it was the most common commercial process until the late 1850s. It was superseded by the collodion process. After reading early reports of Daguerre's invention, Henry Fox Talbot, who had succeeded in creating stabilized photographic negatives on paper in 1835, worked on perfecting his own process. In early 1839, he acquired a key improvement, an effective fixer, from his friend John Herschel, a polymath scientist who had previously shown that hyposulfite of soda (commonly called "hypo" and now known formally as sodium thiosulfate) would dissolve silver salts. News of this solvent also benefited Daguerre, who soon adopted it as a more efficient alternative to his original hot salt water method. A calotype showing the American photographer Frederick Langenheim, circa 1849. Note that the caption on the photo calls the process "Talbotype". Talbot's early silver chloride "sensitive paper" experiments required camera exposures of an hour or more. In 1840, Talbot invented the calotype process, which, like Daguerre's process, used the principle of chemical development of a faint or invisible "latent" image to reduce the exposure time to a few minutes. Paper with a coating of silver iodide was exposed in the camera and developed into a translucent negative image. Unlike a daguerreotype, which could only be copied by rephotographing it with a camera, a calotype negative could be used to make a large number of positive prints by simple contact printing. The calotype had yet another distinction compared to other early photographic processes, in that the finished product lacked fine clarity due to its translucent paper negative. This was seen as a positive attribute for portraits because it softened the appearance of the human face. Talbot patented this process, which greatly limited its adoption, and spent many years pressing lawsuits against alleged infringers. He attempted to enforce a very broad interpretation of his patent, earning himself the ill will of photographers who were using the related glass-based processes later introduced by other inventors, but he was eventually defeated. Nonetheless, Talbot's developed-out silver halide negative process is the basic technology used by chemical film cameras today. Hippolyte Bayard had also developed a method of photography but delayed announcing it, and so was not recognized as its inventor. In 1839, John Herschel made the first glass negative, but his process was difficult to reproduce. Slovene Janez Puhar invented a process for making photographs on glass in 1841; it was recognized on June 17, 1852 in Paris by the Académie Nationale Agricole, Manufacturière et Commerciale. In 1847, Nicephore Niépce's cousin, the chemist Niépce St. Victor, published his invention of a process for making glass plates with an albumen emulsion; the Langenheim brothers of Philadelphia and John Whipple and William Breed Jones of Boston also invented workable negative-on-glass processes in the mid-1840s. In 1851 Frederick Scott Archer invented the collodion process. Photographer and children's author Lewis Carroll used this process. (Carroll refers to the process as "Tablotype" [sic] in the story "A Photographer's Day Out") Roger Fenton's assistant seated on Fenton's photographic van, Crimea, 1855 Herbert Bowyer Berkeley experimented with his own version of collodion emulsions after Samman[disambiguation needed] introduced the idea of adding dithionite to the pyrogallol developer. Berkeley discovered that with his own addition of sulfite, to absorb the sulfur dioxide given off by the chemical dithionite in the developer, that dithionite was not required in the developing process. In 1881 he published his discovery. Berkeley's formula contained pyrogallol, sulfite and citric acid. Ammonia was added just before use to make the formula alkaline. The new formula was sold by the Platinotype Company in London as Sulpho-Pyrogallol Developer. Nineteenth-century experimentation with photographic processes frequently became proprietary. The German-born, New Orleans photographer Theodore Lilienthal successfully sought legal redress in an 1881 infringement case involving his "Lambert Process" in the Eastern District of Louisiana. General view of The Crystal Palace at Sydenham by Philip Henry Delamotte, 1854 A mid-19th century "Brady stand" armrest table, used to help subjects keep still during long exposures. It was named for famous US photographer Mathew Brady. An 1855 cartoon satirized problems with posing for Daguerreotypes: slight movement during exposure resulted in blurred features, red-blindness made rosy complexions look dark. In this 1893 multiple-exposure trick photo, the photographer appears to be photographing himself. It satirizes studio equipment and procedures that were nearly obsolete by then. Note the clamp to hold the sitter's head still. A comparison of common print sizes used in photographic studios during the 19th century The daguerreotype proved popular in response to the demand for portraiture that emerged from the middle classes during the Industrial Revolution. This demand, which could not be met in volume and in cost by oil painting, added to the push for the development of photography. Roger Fenton and Philip Henry Delamotte helped popularize the new way of recording events, the first by his Crimean war pictures, the second by his record of the disassembly and reconstruction of The Crystal Palace in London. Other mid-nineteenth-century photographers established the medium as a more precise means than engraving or lithography of making a record of landscapes and architecture: for example, Robert Macpherson's broad range of photographs of Rome, the interior of the Vatican, and the surrounding countryside became a sophisticated tourist's visual record of his own travels. In America, by 1851 a broadside by daguerreotypist Augustus Washington was advertising prices ranging from 50 cents to $10. However, daguerreotypes were fragile and difficult to copy. Photographers encouraged chemists to refine the process of making many copies cheaply, which eventually led them back to Talbot's process. Ultimately, the photographic process came about from a series of refinements and improvements in the first 20 years. In 1884 George Eastman, of Rochester, New York, developed dry gel on paper, or film, to replace the photographic plate so that a photographer no longer needed to carry boxes of plates and toxic chemicals around. In July 1888 Eastman's Kodak camera went on the market with the slogan "You press the button, we do the rest". Now anyone could take a photograph and leave the complex parts of the process to others, and photography became available for the mass-market in 1901 with the introduction of the Kodak Brownie. The first durable color photograph, taken by Thomas Sutton in 1861 A practical means of color photography was sought from the very beginning. Results were demonstrated by Edmond Becquerel as early as 1848, but exposures lasting for hours or days were required and the captured colors were so light-sensitive they would only bear very brief inspection in dim light. The first durable color photograph was a set of three black-and-white photographs taken through red, green, and blue color filters and shown superimposed by using three projectors with similar filters. It was taken by Thomas Sutton in 1861 for use in a lecture by the Scottish physicist James Clerk Maxwell, who had proposed the method in 1855. The photographic emulsions then in use were insensitive to most of the spectrum, so the result was very imperfect and the demonstration was soon forgotten. Maxwell's method is now most widely known through the early 20th century work of Sergei Prokudin-Gorskii. It was made practical by Hermann Wilhelm Vogel's 1873 discovery of a way to make emulsions sensitive to the rest of the spectrum, gradually introduced into commercial use beginning in the mid-1880s. Two French inventors, Louis Ducos du Hauron and Charles Cros, working unknown to each other during the 1860s, famously unveiled their nearly identical ideas on the same day in 1869. Included were methods for viewing a set of three color-filtered black-and-white photographs in color without having to project them, and for using them to make full-color prints on paper. The first widely used method of color photography was the Autochrome plate, a process inventors and brothers Auguste and Louis Lumière began working on in the 1890s and commercially introduced in 1907. It was based on one of Louis Ducos du Hauron's ideas: instead of taking three separate photographs through color filters, take one through a mosaic of tiny color filters overlaid on the emulsion and view the results through an identical mosaic. If the individual filter elements were small enough, the three primary colors of red, blue, and green would blend together in the eye and produce the same additive color synthesis as the filtered projection of three separate photographs. A color portrait of Samuel Clemens (Mark Twain) by Alvin Langdon Coburn, 1908, made by the recently introduced Autochrome process Autochrome plates had an integral mosaic filter layer with roughly five million previously dyed potato grains per square inch added to the surface. Then through the use of a rolling press, five tons of pressure were used to flatten the grains, enabling every one of them to capture and absorb color and their microscopic size allowing the illusion that the colors are merged together. The final step was adding a coat of the light capturing substance silver bromide after which a color image could be imprinted and developed. In order to see it, reversal processing was used to develop each plate into a transparent positive that could be viewed directly or projected with an ordinary projector. One of the drawbacks of the technology is an exposure time of at least a second was required during the day in bright light and the worse the light is, the time required quickly goes up. An indoor portrait required a few minutes with the subject not being able to move or else the picture would come out blurry. This was because the grains absorbed the color fairly slowly and that a filter of a yellowish-orange color was added to the plate to keep the photograph from coming out excessively blue. Although necessary, the filter had the effect of reducing the amount of light that was absorbed. Another drawback was that the film could only be enlarged so much until the many dots that make up the image become apparent. Competing screen plate products soon appeared and film-based versions were eventually made. All were expensive and until the 1930s none was "fast" enough for hand-held snapshot-taking, so they mostly served a niche market of affluent advanced amateurs. A new era in color photography began with the introduction of Kodachrome film, available for 16 mm home movies in 1935 and 35 mm slides in 1936. It captured the red, green, and blue color components in three layers of emulsion. A complex processing operation produced complementary cyan, magenta, and yellow dye images in those layers, resulting in a subtractive color image. Maxwell's method of taking three separate filtered black-and-white photographs continued to serve special purposes into the 1950s and beyond, and Polachrome, an "instant" slide film that used the Autochrome's additive principle, was available until 2003, but the few color print and slide films still being made in 2015 all use the multilayer emulsion approach pioneered by Kodachrome. Main article: Digital photography Walden Kirsch as scanned into the SEAC computer in 1957 In 1957, a team led by Russell A. Kirsch at the National Institute of Standards and Technology developed a binary digital version of an existing technology, the wirephoto drum scanner, so that alphanumeric characters, diagrams, photographs and other graphics could be transferred into digital computer memory. One of the first photographs scanned was a picture of Kirsch's infant son Walden. The resolution was 176x176 pixels with only one bit per pixel, i.e., stark black and white with no intermediate gray tones, but by combining multiple scans of the photograph done with different black-white threshold settings, grayscale information could also be acquired. The charge-coupled device (CCD) is the image-capturing optoelectronic component in first-generation digital cameras. It was invented in 1969 by Willard Boyle and George E. Smith at AT&T Bell Labs as a memory device. The lab was working on the Picturephone and on the development of semiconductor bubble memory. Merging these two initiatives, Boyle and Smith conceived of the design of what they termed "Charge 'Bubble' Devices". The essence of the design was the ability to transfer charge along the surface of a semiconductor. It was Dr. Michael Tompsett from Bell Labs however, who discovered that the CCD could be used as an imaging sensor. The CCD has increasingly been replaced by the active pixel sensor (APS), commonly used in cell phone cameras. These mobile phone cameras are used by billions of people worldwide, dramatically increasing photographic activity and material and also fueling citizen journalism. The web has been a popular medium for storing and sharing photos ever since the first photograph was published on the web by Tim Berners-Lee in 1992 (an image of the CERN house band Les Horribles Cernettes). Today sites and apps such as Flickr, Picasa, Instagram, Imgur and PhotoBucket are used by many millions of people to share their pictures. ^ This date is commonly misreported as 1725 or 1727, an error deriving from the belief that a 1727 publication of Schulze's account of experiments he says he undertook about two years earlier is the original source. In fact, it is a reprint of a 1719 publication and the date of the experiments is therefore circa 1717. The dated contents page of the true original can be seen here (retrieved 21 February 2015)
Digital Printing: A Better Avenue For Quality Four Color Printing Color Brochure Printing(Redirected from Megapixel) This example shows an image with a portion greatly enlarged, in which the individual pixels are rendered as small squares and can easily be seen. A photograph of sub-pixel display elements on a laptop's LCD screen In digital imaging, a pixel, pel, dots, or picture element is a physical point in a raster image, or the smallest addressable element in an all points addressable display device; so it is the smallest controllable element of a picture represented on the screen. The address of a pixel corresponds to its physical coordinates. LCD pixels are manufactured in a two-dimensional grid, and are often represented using dots or squares, but CRT pixels correspond to their timing mechanisms . Each pixel is a sample of an original image; more samples typically provide more accurate representations of the original. The intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as red, green, and blue, or cyan, magenta, yellow, and black. In some contexts (such as descriptions of camera sensors), the term pixel is used to refer to a single scalar element of a multi-component representation (more precisely called a photosite in the camera sensor context, although the neologism sensel is sometimes used to describe the elements of a digital camera's sensor), while in yet other contexts the term may be used to refer to the set of component intensities for a spatial position. Drawing a distinction between pixels, photosites, and samples may reduce confusion when describing color systems that use chroma subsampling or cameras that use Bayer filter to produce color components via upsampling. The word pixel is based on a contraction of pix (from word "pictures", where it is shortened to "pics", and "cs" in "pics" sounds like "x") and el (for "element"); similar formations with 'el' include the words voxel and texel. The word "pixel" was first published in 1965 by Frederic C. Billingsley of JPL, to describe the picture elements of video images from space probes to the Moon and Mars. Billingsley had learned the word from Keith E. McFarland, at the Link Division of General Precision in Palo Alto, who in turn said he did not know where it originated. McFarland said simply it was "in use at the time" (circa 1963). The word is a combination of pix, for picture, and element. The word pix appeared in Variety magazine headlines in 1932, as an abbreviation for the word pictures, in reference to movies. By 1938, "pix" was being used in reference to still pictures by photojournalists. The concept of a "picture element" dates to the earliest days of television, for example as "Bildpunkt" (the German word for pixel, literally 'picture point') in the 1888 German patent of Paul Nipkow. According to various etymologies, the earliest publication of the term picture element itself was in Wireless World magazine in 1927, though it had been used earlier in various U.S. patents filed as early as 1911. Some authors explain pixel as picture cell, as early as 1972. In graphics and in image and video processing, pel is often used instead of pixel. For example, IBM used it in their Technical Reference for the original PC. Pixilation, spelled with a second i, is an unrelated filmmaking technique that dates to the beginnings of cinema, in which live actors are posed frame by frame and photographed to create stop-motion animation. An archaic British word meaning "possession by spirits (pixies)," the term has been used to describe the animation process since the early 1950s; various animators, including Norman McLaren and Grant Munro, are credited with popularizing it. A pixel does not need to be rendered as a small square. This image shows alternative ways of reconstructing an image from a set of pixel values, using dots, lines, or smooth filtering. A pixel is generally thought of as the smallest single component of a digital image. However, the definition is highly context-sensitive. For example, there can be "printed pixels" in a page, or pixels carried by electronic signals, or represented by digital values, or pixels on a display device, or pixels in a digital camera (photosensor elements). This list is not exhaustive and, depending on context, synonyms include pel, sample, byte, bit, dot, and spot. Pixels can be used as a unit of measure such as: 2400 pixels per inch, 640 pixels per line, or spaced 10 pixels apart. The measures dots per inch (dpi) and pixels per inch (ppi) are sometimes used interchangeably, but have distinct meanings, especially for printer devices, where dpi is a measure of the printer's density of dot (e.g. ink droplet) placement. For example, a high-quality photographic image may be printed with 600 ppi on a 1200 dpi inkjet printer. Even higher dpi numbers, such as the 4800 dpi quoted by printer manufacturers since 2002, do not mean much in terms of achievable resolution. The more pixels used to represent an image, the closer the result can resemble the original. The number of pixels in an image is sometimes called the resolution, though resolution has a more specific definition. Pixel counts can be expressed as a single number, as in a "three-megapixel" digital camera, which has a nominal three million pixels, or as a pair of numbers, as in a "640 by 480 display", which has 640 pixels from side to side and 480 from top to bottom (as in a VGA display), and therefore has a total number of 640×480 = 307,200 pixels or 0.3 megapixels. The pixels, or color samples, that form a digitized image (such as a JPEG file used on a web page) may or may not be in one-to-one correspondence with screen pixels, depending on how a computer displays an image. In computing, an image composed of pixels is known as a bitmapped image or a raster image. The word raster originates from television scanning patterns, and has been widely used to describe similar halftone printing and storage techniques. For convenience, pixels are normally arranged in a regular two-dimensional grid. By using this arrangement, many common operations can be implemented by uniformly applying the same operation to each pixel independently. Other arrangements of pixels are possible, with some sampling patterns even changing the shape (or kernel) of each pixel across the image. For this reason, care must be taken when acquiring an image on one device and displaying it on another, or when converting image data from one pixel format to another. For example: Text rendered using ClearType Computers can use pixels to display an image, often an abstract image that represents a GUI. The resolution of this image is called the display resolution and is determined by the video card of the computer. LCD monitors also use pixels to display an image, and have a native resolution. Each pixel is made up of triads, with the number of these triads determining the native resolution. On some CRT monitors, the beam sweep rate may be fixed, resulting in a fixed native resolution. Most CRT monitors do not have a fixed beam sweep rate, meaning they do not have a native resolution at all - instead they have a set of resolutions that are equally well supported. To produce the sharpest images possible on an LCD, the user must ensure the display resolution of the computer matches the native resolution of the monitor. The pixel scale used in astronomy is the angular distance between two objects on the sky that fall one pixel apart on the detector (CCD or infrared chip). The scale s measured in radians is the ratio of the pixel spacing p and focal length f of the preceding optics, s=p/f. (The focal length is the product of the focal ratio by the diameter of the associated lens or mirror.) Because p is usually expressed in units of arcseconds per pixel, because 1 radian equals 180/π*3600≈206,265 arcseconds, and because diameters are often given in millimeters and pixel sizes in micrometers which yields another factor of 1,000, the formula is often quoted as s=206p/f. Main article: Color depth The number of distinct colors that can be represented by a pixel depends on the number of bits per pixel (bpp). A 1 bpp image uses 1-bit for each pixel, so each pixel can be either on or off. Each additional bit doubles the number of colors available, so a 2 bpp image can have 4 colors, and a 3 bpp image can have 8 colors: ... For color depths of 15 or more bits per pixel, the depth is normally the sum of the bits allocated to each of the red, green, and blue components. Highcolor, usually meaning 16 bpp, normally has five bits for red and blue, and six bits for green, as the human eye is more sensitive to errors in green than in the other two primary colors. For applications involving transparency, the 16 bits may be divided into five bits each of red, green, and blue, with one bit left for transparency. A 24-bit depth allows 8 bits per component. On some systems, 32-bit depth is available: this means that each 24-bit pixel has an extra 8 bits to describe its opacity (for purposes of combining with another image). Geometry of color elements of various CRT and LCD displays; phosphor dots in a color CRTs display (top row) bear no relation to pixels or subpixels. Many display and image-acquisition systems are, for various reasons, not capable of displaying or sensing the different color channels at the same site. Therefore, the pixel grid is divided into single-color regions that contribute to the displayed or sensed color when viewed at a distance. In some displays, such as LCD, LED, and plasma displays, these single-color regions are separately addressable elements, which have come to be known as subpixels. For example, LCDs typically divide each pixel vertically into three subpixels. When the square pixel is divided into three subpixels, each subpixel is necessarily rectangular. In display industry terminology, subpixels are often referred to as pixels, as they are the basic addressable elements in a viewpoint of hardware, and hence pixel circuits rather than subpixel circuits is used. Most digital camera image sensors use single-color sensor regions, for example using the Bayer filter pattern, and in the camera industry these are known as pixels just like in the display industry, not subpixels. For systems with subpixels, two different approaches can be taken: This latter approach, referred to as subpixel rendering, uses knowledge of pixel geometry to manipulate the three colored subpixels separately, producing an increase in the apparent resolution of color displays. While CRT displays use red-green-blue-masked phosphor areas, dictated by a mesh grid called the shadow mask, it would require a difficult calibration step to be aligned with the displayed pixel raster, and so CRTs do not currently use subpixel rendering. The concept of subpixels is related to samples. Diagram of common sensor resolutions of digital cameras including megapixel values Marking on a camera phone that has about 2 million effective pixels. A megapixel (MP) is a million pixels; the term is used not only for the number of pixels in an image, but also to express the number of image sensor elements of digital cameras or the number of display elements of digital displays. For example, a camera that makes a 2048×1536 pixel image (3,145,728 finished image pixels) typically uses a few extra rows and columns of sensor elements and is commonly said to have "3.2 megapixels" or "3.4 megapixels", depending on whether the number reported is the "effective" or the "total" pixel count. Digital cameras use photosensitive electronics, either charge-coupled device (CCD) or complementary metal–oxide–semiconductor (CMOS) image sensors, consisting of a large number of single sensor elements, each of which records a measured intensity level. In most digital cameras, the sensor array is covered with a patterned color filter mosaic having red, green, and blue regions in the Bayer filter arrangement, so that each sensor element can record the intensity of a single primary color of light. The camera interpolates the color information of neighboring sensor elements, through a process called demosaicing, to create the final image. These sensor elements are often called "pixels", even though they only record 1 channel (only red, or green, or blue) of the final color image. Thus, two of the three color channels for each sensor must be interpolated and a so-called N-megapixel camera that produces an N-megapixel image provides only one-third of the information that an image of the same size could get from a scanner. Thus, certain color contrasts may look fuzzier than others, depending on the allocation of the primary colors (green has twice as many elements as red or blue in the Bayer arrangement). DxO Labs invented the Perceptual MegaPixel (P-MPix) to measure the sharpness that a camera produces when paired to a particular lens – as opposed to the MP a manufacturer states for a camera product which is based only on the camera's sensor. The new P-MPix claims to be a more accurate and relevant value for photographers to consider when weighing-up camera sharpness. As of mid-2013, the Sigma 35mm F1.4 DG HSM mounted on a Nikon D800 has the highest measured P-MPix. However, with a value of 23 MP, it still wipes-off more than one-third of the D800's 36.3 MP sensor. A camera with a full-frame image sensor, and a camera with an APS-C image sensor, may have the same pixel count (for example, 16 MP), but the full-frame camera may allow better dynamic range, less noise, and improved low-light shooting performance than an APS-C camera. This is because the full-frame camera has a larger image sensor than the APS-C camera, therefore more information can be captured per pixel. A full-frame camera that shoots photographs at 36 megapixels has roughly the same pixel size as an APS-C camera that shoots at 16 megapixels. One new method to add Megapixels has been introduced in a Micro Four Thirds System camera which only uses 16MP sensor, but can produce 64MP RAW (40MP JPEG) by expose-shift-expose-shift the sensor a half pixel each time to both directions. Using a tripod to take level multi-shots within an instance, the multiple 16MP images are then generated into a unified 64MP image.
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